Electrical device for the heating of rooms



March 26, 1935. -r5

ELECTRICAL DEVICE FOR THE HEATING OF ROOMS Filed May 15, 19253 3 Sheets-Sheet l I/I/ l I W 3 1 Z 2/1 Z March 26,1935. E, RUNTE 1,995,581

ELECTRICAL DEVICE FOR THE HEATING 0F ROOMS Filed May 15, 1933 3 Sheets-Sheet 2 1 [My WM l IN I Ii. hsi

March 26, 1935.

E. RUNTE 1,995,581

ELECTRICAL DEVICE FOR THE HEATING OF ROOMS 3 Sheets-Sheet 3 Filed May 15, 19s:

Patented Mar. 26, 1935 UNITED STATES PATENT OFFICE Egon Blnte, Zurich, Switaerland Application May 15, 1933,

Serial No. 671,226

In Switzerland October 12, 1932 4 Claims.

This invention relates to electrical devices for the heating of rooms.

For the heating of rooms by electricity, hitherto, heaters comprising resistance means adapted .to be heated up to high temperatures were used, or

else heaters with indirectly heated surfaces. Both of these two kinds of heating devices are, however, unsatisfactory, in respect of efilciency for the following reasons:

In order to obtain a high degree of efliciency it is essential that heat losses are reduced. to a minimum. Most of the heat losses accrue from the heat transmitted to walls and ceilings of the rooms being conducted outwardly. Thus, an excessive heat transmission to the walls and ceilings must be prevented. To this end heat radiation at high temperatures must be avoided as much as possible.

In exchanging the heat by convection, it is necessary for minimizing the heat losses that the temperature of the air be maintained throughout the room at the same desired height without exceptions of portions of higher temperatures, as

the more the temperature of individual portions of the air is raised the smaller the proportion of heated air will be. Thus, the greater the difference between the temperatures of the air, the ceilings or the walls respectively, the more heat will be transmitted tothe ceilings or to the walls,

most of which goes lost.

It has already been proposed to use an electric low temperature resistance means which heats up to less than 50 C. and consists in a coat constituted by a substance containing. carbon, for example in the form of graphite, the coat being applied to an insulating material, as cardboard, paper and the like. Aside from the impossibility of producing in actual practice a uniform coat offering a constant resistance throughout, it is obvious that the heating effect of a superficial heater of this kind is but small, due to a part of the heat being dissipated by heat conduction of the carrier.

With the electrical device for the heating of rooms, according to the invention, the heat losses are considerably reduced by providing low temperature heating means comprising bare resistance conductors having a relatively large heating surface as compared to the specific strength of the current carried by the conductors, so that for example the temperature of the same is prevented from rising above approximately 50 C., and the conductors are adapted for direct heat transmission to the surrounding air.

Heretoiore, low temperature resistance members were used in practice only for indirect surface heating, as: for example in electrically heated cushions, with a view to prevent the combustible materials of which the cushion is made from catching fire.

Advantageously, the low temperature heating means is composedof sheet metal elements which are apertured alternately from one or the other longitudinal edge in the form of inwardly extending slots, so that each sheet metal element provides a zig-zag shaped electrical conductor.

A preferred form of the invention is distinguished by the provision of including at least one element of the low temperature resistance means in a pipe frame in the manner of a panel, and 5 a plurality of individual pipe frames being arranged side by side to constitute a heater of an aspect similar to a radiator. These pipe frames serve at the same time for protecting the heating elements against mechanical destruction.

Alternatively, the individual pipe frames may be interconnected in the manner of a pipe conduit adapted to be passed by a cooling medium, in order to permit of the device being used for cooling purposes also.

It is known to conduct a cooling medium through the radiators ordinarily applied for hot water heating systems, so as to permit of using the radiators not only for heating purposes in wintertime, but also for cooling purposes in summertime. In eontradistinction thereto, by means 01' this invention, it is not intended to use radiators for cooling purposes, but rather the frame of a device for electrical room heating, by means of low temperature resistance elements, whereby the frame is given a form similar to a radiator.

In the accompanying drawings several constructional forms of an electrical heater according to the invention are illustrated by way of example only in which Fig. 1 is a view of a sheet metal plate serving as a work blank for the manufacture of the resistance of a first constructional form of the invention;

Fig. 2 is a perspective view of a plurality of these sheet metal resistance elements united into a pack;

Fig. 3 shows an elevation of an assembly of these sheet metal resistance elements constituting a heater;

Figs. 4 and 5 represent wiring diagrams, for the heater as per Fig. 3, showing two different modes of connecting up the resistance elements;

Fig. 6 shows a sectional elevation of a second constructional form of the invention, the secremoved;

Fig. 9 shows a side elevation of Fig. 8;

Fig. 10 shows a section on the line- X X in Fig. 8 on a larger scale, and y Fig. 11 is a view of a modification of Fig. 10.

In the constructional form of the invention shown in the Figs. 1 to 5, 11 denotesa sheet metal plate the two longitudinal edges ofwhich are alternately apertured in the form of slots 12 extending inwardly from these edges, so that each sheet metal plate provides a zig-zag shaped elec trical conductor adapted for use as aheating'elemerit. As the surface temperature of these heating elements is regulated so as not substantially to exceed 50 C., and preferably to remain at about'30 0., any suitable material 'can be used for the resistance elements, even ordinary sheet -iron. If desired other materials'maybe used. Wider slots oraperture 13 are provided in the sheet metal plate 11 regular distances apart, in

such manner, that the distance between two apertures13 corresponds to the lengthof a resistance element 10 and thus'to the height of the pack to be formed (Fig. 2).

ered by pushing a folded strip 15 of insulating material such as press-span, over each longitudinal edge of the slitted metal strip between the wider slots. In this manner the apertured longitudinal edges of the zig-zag shaped resistance elements are steadied. I

The thus prepared work blank for the resistance is then folded to form a pack as shown in Fig.2

so that the connecting strips 16 between each two adjacent resistance elements 10 are alternately for contacting with the sheet metal current carryingresistan'ce' elements, whereas the outer portions of "these frames may consist of metal. 19 designates one of the terminal members of the resistance, the other terminal member being situated on the backside of the pack.

The Fig. 3 shows four resistor sections as per Fig.2 to be united to forma heater. The frame 20 of the thus formed heater is apertured on all of its sides in such a manner that the surrounding air has free access to the elements and the heat produced in the heater is transmitted tothe air directly. 21 denote grip members for handling the heater. 22 designates. an electric control switch for regulating the temperature of the heater.

Fig. 4 illustrates in a schematical manner the four sections of the heater to be connected in parallel in groups each comprising two sectionsccnnected in series. With the manner of connecting up the, sections of the heater, as

shown in Fig. 5, a somewhat lesser heating effect is obtained, in that three sections I, II, III of the heater connected up in parallel are connected in series with the fourth section IV. It is obvious that any possible combination for connecting up "the sections, may be adaptedas connecting the The longitudinal marginal portions of each resistance element 10 aregovfour sections all in parallel or in series and so forth.

Depending on the configuration of the rooms to be heated, the individual heater sections can be disposed in any suitable manner. It is not absolutely necessary that the resistance of the heater, as shown in Fig. 2, is made in one throughout. If desired the individual resistance elements may also be joined together by soldered or other electricity conducting connections.

, Heaters of the just described construction are distinguished by a very large heating surface, thus, a heater of the overall dimensions of 55 x x 12 centimeters has an effective surface of more than 5 square meters.

In the second constructional form of the in: vention, as shown in the Figs. 6 and '7, every twoheating elements 10 are secured in spaced relationship to four clips 24 clamped on individual pipe frames 23. Several such frames 23 are united to form a system with the frames arranged beside each other, and the clips 24 are provided with holes for the reception of through bolts 25 for'staying the system. For the same purpose through bolts 23 are passed through clips 24 disposed at the top of the frames 23 and embracing the upper members thereof. The through bolts 25 are provided with nuts 26 by means of which the clips 24 are compressed for holding the resistance elements 10 between their open ends and at the same time for being clamped on the pipe frames 23. To each of the two end frames 23 a closureplate 2'7 is secured by sliding the plates on the ends of the lower bolts 23 and screwing a nut on each bolt end. The control switch 28 for connecting and disconnecting the heater may be arranged on either closure plate.

-of a plug'contact 30. The end frames 23 are further provided with-legs 31 each made of a piece of .pipe and secured to these frames for example by welding.

The constructional form of the invention as per the Figs. 8 to 11 distinguishes from that shown in the Figs. 6 and 7 by the lower members of the individual pipe frames being advantageous-v ly provided with a partition wall 32 for closing the free passage of these members and being (Fig. 10) situated in the vertical longitudinal middle plane of the heater. On opposite sides of each partition wall and on both sides of each pipe frame pipe studs 33 are arranged the free ends of which are provided with a conical face to fit a counter face on the corresponding pipe stud of the adjacent pipe frame in interengaging manner, thus connecting the pipe frames to form a continuous pipe system. The end frames 23 are provided with pipe connections '34 with which supply conduits for a coolingmedium are connected, so as to permit of using the device not only for heating, but also for cooling purposes. In the modification illustrated in Fig. 11, the

lower-member of each frame is provided on both sides of the member and on opposite sides of the partition wall 32 with pipe studs 33', 33" respectively, these studs communicating with the corresponding studs of the adjacent frames. By virtue of this arrangement, a circulation of the cooling medium is obtained which begins with the cooling medium flowing at first through the respective pipe frame to leave this frame through the pipe stud on the other side of the partition wall, whereupon the medium enters the next pipe frame to pass through the same as previously described except of the direction of the flow and so forth. In this manner the frames are connected in series to be successively passed by the cooling medium. For pressing the pipe studs 33, 33" against each other in a liquid-tight manner, through bolts, as shown at 35, for interconnecting the frames, may be arranged to extend across the frames in the longitudinal direction of the heater.

I do not limit myself to the particular size shape, number or arrangement of parts as shown and described, all of which may be varied without going beyond the scope of my invention as shown, described and claimed.

What I claim is:

1. In an electrical device for the heating of rooms, the combination with a frame constituted by a system of individual pipe frames arranged side by side and having the aspect of a radiator, a lower member of each pipe frame, a partition wall inserted in each of said lower members for closing the free passage thereof, two pipe connections disposed on opposite sides of said partition wall to both sides of the respective pipe frame for interconnecting adjacent pipe frames, with corresponding pipe connections joined together, to provide a conduit adapted for circulating a cooling medium therethrough when the device is to be used as a cooler, of a low temperature heating resistance inserted in said frame and comprising resistance elements in the form of bare conductors having a relatively large heating surface as compared to the specific strength of the current carried by said conductors, and means for securing at least one of said resistance elements to each of said pipe frames in the manner of a panel surrounded by the respective pipe frame.

2. In an electrical device for the heating of rooms, the combination with a frame constituted by a system of individual pipe frames arranged side by side and having the aspect of a radiator, a lower member of each pipe frame, a partition wall inserted in each of said lower members for closing the free passage thereof, a pipe connection disposed on opposite sides of said partition wall to both sides of the respective pipe frame for interconnecting adjacent pipe frames, with corresponding pipe connections joined together, to provide a conduit with succeeding pipe frames connected in series, and adapted for circulating a cooling medium therethrough when the device is to be used as a cooler, of a low temperature heating resistance inserted in said frame and comprising resistance elements in the form of bare conductors having a relatively large heating surface as compared to the specific strength of the current carried by said conductors, and means for securing at least one of said resistance elements to each of said pipe frames in the manner of a panel surrounded by the respective pipe frame.

3. An electric heater, comprising a low temperature heating resistance of bare conductors having a surface of such an extent that they heat to an average temperature of approximately 50 C. under the electric load for which the heater is rated, said conductors consisting of metal sheets slotted to constitute zig-zag shaped conductors, vertically arranged pipe frames in each of which at least one of said metal sheets is mounted, said pipe frames being arranged at distances from each other, whereby shafts are formed between the adjacent metal sheets and the adjacent pipe frames, said shafts providing for free access of the air to be heated and for unrestricted flow of the latter.

4-. An electric heater, comprising a lower temperature heating resistance of bare conductors having a surface of such an extent that they heat to an average temperature of approximately 50 C. under the electric load for which the heater is rated, said conductors consisting of sheet iron elements slotted to constitute zig-zag shaped conductors, vertically arranged pipe frames in each of which at least one of said sheet iron elements is mounted, said pipe frames being arranged at distances from each other, whereby shafts are formed between the adjacent sheet iron elements and composed of two heating surfaces, the interstices between said pipe frames forming the continuation of such shafts, the latter providing for free access of the air to be heated and for unrestricted flow of the latter.

EGON RUNTE. 

